Photochromic compound

ABSTRACT

IN WHICH R CAN BE HYDROGEN, A HALOGEN, A CYAN GROUP, A NITRO GROUP, AN ALKYL GROUP (1-8 CARBONS), AN ALKOXY GROUP (1-8 CARBONS) OR AN ALKOXY CARBONYL GROUP (1-8 CARBONS). VARIOUS RESIN AND SOLVENT SYSTEMS WHICH FORM PHOTOCHROMIC COMPOSITIONS WITH THE ABOVE COMPOUND ARE DESCRIBED IN THE SPECIFICATION. THE COMPOUND OR COMPOSITION WILL VARY FROM COLORLESS (NON-EXCITED) TO BLUE (UNDER ULTRAVIOLET), AND EXHIBITS HIGH REVERSIBILITY.   A PHOTOCHROMIC COMPOUND REPRESENTED BY THE FORMULA:   (2,3-B)-1,4-OXAZINE)   SPIRO(1,3-(1,3,3-TRIS(CH3-),5-R-INDOLE)-2,2&#39;&#39;(2&#39;&#39;H)-NAPHTH-

May 11, 1971 HlsA'rAKE oNo E rAL 3,578,602

PHOTOCHROMIC COMPOUND Filed Aug. 29, 196e DENSITY T- n--n---I---T--- 40oI soo 59o soo (mp) wAvs LENGTH DENSITY 40ov soo 59o soo (mp) wAvE LENGTH INVENTORS HISATAKE ONO TIAKI OSADA KUNIKO KOSUGE f. 3,578,002 Ice Patented May 1l, 1971 3 578 602 acetonitrile and dirnethylformamide, and their photochro- PHGTOCHR COMPUND mic property is'no longer pronounced, even if ultraviolet Hisatake Ono, 'Tiaki Osada, and Kuniko Kosuge, Asakaradiation 1S radiated upon the Sohmons shi, Japan, assignors to Fuji Shashin Film Kabushiki SUMMARY F THE INVENTION Kaisha, Kanagawa, Japan 5 Filed Aug 29 1963, ser. Nm 756,180 A photochromic compound represented by the formula: Claims priority, application Japan, Aug. 30, 1967, CH3 CH,

42/ss,662 rm. Cl. Gozb 5/24 Us. (1252-300 1 claims lo R =N Vw N l ABSTRACT 0F THE DISCLOSURE CH3 A photochromic compound represented by the formula. in which R can b e hydrogen, a halogen, a cyan group, a CH3 CH3 15 nitro group, an alkyl group (1-8 carbons), an alkoxy R N group (1-8 carbons) or an yalkoxy carbonyl group (1-8 carbons).

Typical resins which may be utilized in combination with the compounds shown above are: polyvinylacetate,

polymethylmethacrylate, polystyrene, nitrocellulose, polyvinyl chloride, cellulose acetate and polyvinylpyrrolidone, in which R can be hydrogen, a halogen, a cyan group, a ethyleelllllose nitro group, an alkyl group (1 8 carbons), an alkoxy Typical solvents for the compounds shown above are: group (1 8 Carbons) or an alkoxy carbonyl group (1 8 25 benzene, toluene, carbon disulde, chloroform, ethylacecarbons). Various resin and solvent systems which form tate, rnethylethylketone, acetone, ethyl alcohol, acetoniphotochromic compositions with the above compound are trile, tetrahydrofuran, dioxane, methyl ether of ethylene described in the specification. The compound or compoglycol, dimethyl formatnide and dimethyl SulfoXidesition will vary from colorless (non-excited) to blue It iS en object of the invention to ProVide e novel Photo' (under ultraviolet), and exhibits high reversibility. 3o Chrornie Compound- It is another object of the invention to provide a photochromic composition which contains the novel photochro- BACKGROUND Op THE INVENTION mic compound of the present invention.

A further object is to overcome the dependence of the 3 photochromic property of a compound upon the solvent This invention relates to a photochromic compound and used.

Field of the invention more particularly to a photochromic compound capable BRIEF DESCRIPTION OF THE DRAWINGS of repeated color formation or discharging under the action of light. FIGS. 1 and 2 illustrate the spectrum change of solu- D f th 4 tions of the compound of the invention at various levels @scriptum o e prior art of radiation exposure. Photochromism is a phenomenon that has drawn atten- DESCRIPTION OF THE PREFERRED tion for some years. Photochromism is generally a revers- EMBODIMENTS ible phenomenon illustrated by a compound which, when n exposed to the radiation of light involving ultraviolet 45 In accordance Wlth the Invention, there 1S ProVlded a rays, such as sunlight, or the light of mercury lamp, rapnovel photochromic Compound represented by the folloW idly changes in color and returns to its original color if ing formule, the radiation is discontinued or the compound is stored CH3 CH3 in the dark. A compound illustrating this property is called a photochromic compound. Various types of 5o R N photochromic compounds have been synthesized but they d generally have no structural similarity. 1,3,3-trimethyl- 0"( indolinobenzospiropyran derivatives represented by the \N following general structure: H3

CH3 CH3 55 in which R is a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkoxy group of l to 8 carbon atoms, an alkyl group of 1 to 8 carbon atoms or an 2 n R1 i alkoxycarbonyl group of 1 to 8 carbon atoms.

NT O

The compound of this invention may be synthesized as follows: A mixture of 5-R-l,3,3-trimethy1-2tmethylene- CH (I) indoline and alpha-nitroso-beta-naphthol (equimolecular in which R1 and R2 are various substituents, have received amounts) iS reflnXed ill ethyl alCOhOl While bubbling nitromuch attention in the art. Generally, the photochromic gen gas therein until reaction completion. The mixture compound represented by the Formula I change rapidly is then cooled to deposit a brown crystal. Recrystallizafrom a colorless state to blue when exposed to sunlight or tlon of this resulting crystal from ethyl alcohol after lterultraviolet radiation in a non-polar solvent such as bening will produce the :foregoing compound at yields of zene or toluene, and will return to the original colorless about l0-30%. t state by being allowed to stand in the dark or in the radi- The compound obtamed 1s then dissolved m solvents ation of certain visible rays. However, these compounds which are colorless at room temperature, such as: benare ordinarily red to red violet when dissolved in polar zene, toluene, carbon disulfide, chloroform, ethyl acetate, solvents such as ethyl alcohol, methyl alcohol, acetone, methyl ethyl ketone, acetone, ethyl alcohol, methyl alco- 3 hol, acetonitrile, tetrahydrofuran, dioxane, methyl Cellosolve, morpholine, ethylene glycol, dimethylformamide and dimethyl sulfoxide. The dissolved compound is then color-formed to blue under ultraviolet radiation. The color forming density will be increased if the ultraviolet radiation is applied while cooling with ice.

The treated compound of the present invention may also be dissolved in solutions which are colorless or transparent, such as a polyvinyl acetate-acetone solution, a nitrocellulose-acetonitrile solution, a polyvinyl chloridemethyl ethyl ketone solution, a polymethyl methacrylateacetone solution, a cellulose acetate-dimethylformamide solution, a polyvinylpyrrolidone-acetonitrile solution, a polystyrene-benzene solution, an ethyl cellulose-methylene chloride solution, and the like and this dissolution is performed independently of the kind of solvent or the resin utilized. The solution formed may be applied to a transparent support, such as cellulose triacetate, polyethylene terephthalate or baryta paper, and dried to obtain a photochromic material, which may be color formed by ultraviolet radiation to blue, and returned to colorless in about ten or more seconds by removing the source of ultraviolet radiation. It has been found that this back reaction from blue to colorless will proceed at a much higher speed than that in the case of a photochromic material using the compound (I) (Rl-:S-H, R2=6'nitro).

A composition containing the compound of this invention can be utilized for photographic photochromic materials which comprise a support with a photochromic lightsensitive layer coated thereon, or a presensitized plate with a photochromic light-sensitive layer coated thereon. In addition, photochromic materials for furnitures may be formed wherein the compound is applied to glass or a curtain. Of course, the photochromic materials of the present invention may be utilized for filters and for decoration, such as lens or glass.

The composition of the invention may be characterized as follows: the composition is generally colorless independently of the kinds of solvent and resin used, but will be immediately color formed to blue ultraviolet radiation and returned to a colorless state in about ten or more seconds by removing the source of ultraviolet radiation, such a color change being repeatable numerous times.

The spectrum change of the above-mentioned compound (under the inuence of radiation containing ultraviolet rays) in a solution is shown in the accompanying drawing. The spectrum measurement visible part of the spectrum was carried out before exposure to ultraviolet radiation (1); after radiation for 4 seconds (2); and after radiation for 8 seconds (3). The compound used was such that R=H in the foregoing general formula. A benzene solution was used for FIG. l and an ethanol solution for FIG. 2. As the light source, a mercury lamp (Toshiba SHL-lOO) was used.

The details of the present invention will be illustrated by the following examples. These examples are illustrative only and are not intended to limit the invention.

EXAMPLE l Percent Found Calculated 4 ethyl alcohol to give 1.9 g. of a yellow crystal melting at ll7-l19 C.

Solution of the resultant material in toluene, carbon disulfide, chloroform, ethyl acetate, methyl ethyl ketone, acetone, ethyl alcohol, methyl alcohol, acetonitrile, tetrahydrofuran, dioxane, methyl Cellosolve, morpholine, ethylene glycol, dimethylformamide and dimethyl sulfoxide were colorless under ordinary conditions, but were blue color formed by ultraviolet radiation and directly returned to a colorless state upon removal of the ultraviolet source.

Solutions of the thus treated material in polyvinyl acetate acetone, nitrocellulose acetonitrile polyvinyl chloride-methyl ethyl ketone, polymethyl methacrylate acetone, cellulose acetate-dimethyl formamide, cellulose acetate-dimethylformamide, polyvinylpyrrolidone-acetonitrile, polystyrene-benzene, ethyl cellulose-methylene chloride, and the like were coated onto individual supports of baryta paper, cellulose triacetate and polyethylene terephthalate and dried. The coated supports were observed to be blue under ultraviolet radiation, and would rapidly return to a colorless state by removal of the ultraviolet source.

EXAMPLE 2 Percent Found Calculated EXAMPLE 3 Percent Found Calculated 3.3 g. of S-methoXy-l,3,3-trimethyl-Z-methyleneindoline and 2.8 g. of alpha-nitroso-beta-naphthol were relluxed in 60 ml. of ethyl alcohol for 2 hours while bubbling nitrogen gas therein. After the reaction, the excess ethyl alcohol was distilled ot and the reaction mixture was cooled to give a crude crystal of S-rnethoXy-l,3,3-trimethylspiro(in dolino 2,3 naphtho(2,1 b) (1,4) oxazine). When the crude crystal was recrystallized from ethyl alcohol, after filtering, 0.9 g. of light brown crystal was obtained, melting at 13G-132 C.

EXAMPLE 4 Percent Found Calculated g. of S-chloro-l,3,3-trimethyl-Z-methyleneindoline 8 2.1 and l. g. of alpha-nitroso-beta-naphthol were refluxed in 30 m1. of ethyl alcohol for 2 hours, as heretofore described. After distilling olf excess ethyl alcohol to a 25% level, the reaction mixture was cooled to obtain 2.8 g. of a crude crystal of -ch1oro-1,3,3-trimethylspiro(indoline- 2,3-naphtho(2,lb) (1,4)oxazine). When the crude crystal was recrystallized from ethyl alcohol, 1.9 g. of a light yellow-white crystal was obtained, melting at 174- l77 C. The properties of the resulting compound were the same as those of Example 1.

What we claim is:

1. A photochromic compound represented by the following general formula:

CH3 CH3 wherein R is a member selected from the group consisting of a hydrogen atom, a halogen atom, a cyan group, a nitro group, an alkyl group having from 1 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms and an alkoxycarbonyl group having from 1 to 8 carbon atoms.

2. The compound of claim 1 which is 1,3,3-trimethylspiro [indolino-2,3 -naphtho[2,1b] (1,4 oxazine] 3. The compound of claim 1 which is 1,3,3,5tetra1neth ylspiro[indolino-2,3'naphtho[2,1-b] (1,4 oxazine] 4. The compound of claim 1 which is 5methoxyl,3,3 trimethylspiro [indolino-2,3 -naphtho[2, l] 1,4) oxazine] 5. A photochromic composition comprising a binder or solvent and a compound represented by the following general formula:

CH3 CH3 wherein R is a member selected from the group consisting of a hydrogen atom, a halogen atom, a cyan group, a nitro group, an alkyl group having irom 1 to 8 carbon atoms, an alkoxy group having from 1 to 8 carbon atoms and an alkoxycarbonyl group having from 1 to 8 carbon atoms.

6. The photochromic composition claimed in claim 5 wherein the binder comprises a member selected from the group consisting of polyvinylacetate, polymethylmethacrylate, polystyrene, nitrocellulose, polyvinylchloride, celluloseacetate, polyvinylpyrrolidone and ethylcellulose.

7. The photochromic composition claimed in claim 5 wherein said solvent comprises a member selected from the group consisting of benzene, toluene, carbon disulde, chloroform, ethyl acetate, methylethylketone, acetone, ethyl alcohol, acetonitrile, tetrahydrofuran, dioxane, the methyl ether of ethylene glycol, dimethyl formamide and dimethyl sulfoxide.

References Cited UNITED STATES PATENTS 3,100,778 8/1963 Berman 96-90 GEORGE F. LESMES, Primary Examiner I. P. BRAMME, Assistant Examiner U.S. Cl. X.R. 

